The present invention relates generally to money operated vending machines and, more particularly, to a multiple column or source machine wherein two stacks loaded with the identical product brand are alternately operated from the same selector switch.
Money operated vending machines for selectively dispensing articles, one at a time, from a plurality of sources are well known. Such vending machines generally comprise a plurality of stacks of articles which may be arranged in columns in side by side or front to back relationship. Upon insertion of the proper amount of money, such as deposit of a suitable coin, credit is established and a dispensing cycle is initiated according to a selection by the customer. In one particular type of machine, a vend motor is cycled during the dispensing cycle and causes a single article to be dispensed from the selected column or source.
In a multiple stack machine, it is sometimes desired to limit the number of actual selections available to the customer by enabling a prime product to be loaded into two stacks controlled by a single customer-operated selector switch, with the two stacks dispensing alternately as the selector switch is operated. This is commonly done to assure a prime product of getting its proper space in the vendor.
By way of particular example, a mechanical mechanism for alternately dispensing articles from a pair of stacks is disclosed in commonly-assigned Payne U.S. Pat. No. 3,904,076. Electrical alternator circuits for the same purpose have also been proposed, for example as are disclosed in Levine U.S. Pat. No. 3,040,928, McCloy U.S. Pat. No. 3,240,386 and Ficken U.S. Pat. No. 3,252,617. In each of the systems disclosed in these three patents, some form of SPDT switch automatically alternates between individual electrically-operated dispensing mechanisms to alternately operate the mechanisms upon actuation of a single manually-operated switch. By way of further example, the Pearce U.S. Pat. No. 3,756,362 discloses a related arrangement wherein a stepping relay sequentially energizes a number of individual vending mechanisms.
In such vending machines, it sometimes happens that a motor-driven vending mechanism stalls or jams during an attempted dispensing of an article. More specifically, under such conditions one of the vend motors does not complete its cycle of operation, and an associated cam-operated switch does not return to its resting condition. In such event, it is highly desirable that the machine not be fully disabled, and that the remaining product selections remain operative. In view of this, typical prior art vending machine circuits and mechanisms allow alternative selection of articles when one selection is stalled or jammed. Exemplary circuits for use in machines of the type wherein dispensing from each column is controlled by a vend motor arranged to be energized during the latter (vending) portion of its vend cycle through a cam-operated timer switch are disclosed in the following commonly-assigned U.S. Pats.: Camp, No. 3,349,881, Bowman, No. 3,486,601, and Lindsey et al, No. 4,220,235.
It is also desirable to provide a similar feature where two columns are alternately operated from a single selector switch. In other words, if the vend mechanism of one of the two interconnected columns stalls or jams, it is desirable that the alternating operation end and that all remaining vending be accomplished from the non-jammed product selection until all articles are sold out. In accordance with the present invention, this particular problem is recognized, and a highly effective solution provided.